1. Field
The present invention relates generally to near field communication (NFC). More specifically, the present invention relates to NFC transceivers including adaptive antenna matching circuitry.
2. Background
Near Field Communication (NFC) is wireless technology that can enable for short range exchange of information between two or more devices. Devices capable of NFC can simplify presence-oriented transactions to enable for rapid and more secure exchange of information, for example, as in purchases for goods and services, or the exchange of information therein.
As a person skilled in the art will appreciate and understand, NFC technologies communicate over magnetic field induction, where at least two loop antennas are located within each other's “near field,” effectively forming an air-core transformer that operates within a globally available and unlicensed radio frequency which, as indicated, is an industrial, scientific and medical (ISM) band of 13.56 MHz, with a band width of almost two (2) MHz.
Use of Near Field Communication (NFC) technology is steadily increasing. Further, mobile telephones, which differ in shape and size, are becoming smaller and smaller. Additionally, mobile telephones are required to include one or more antennas, which have to fit within the mobile telephone. Accordingly, standardized NFC antenna designs are not a valid option. As a result, non-standardized antennas may have varying characteristics, such as inductance and resistance. Current NFC transmission modules may require antenna circuitry, which is to be manually matched with the integrated circuit (IC) to maximize the power of the emitted RF (radio frequency) field. Therefore, the range of the transmission module may be increased and the quality of the transmitted signal may be enhanced. Manual matching of the antenna characteristics is a rather lengthy and complicated procedure. Further, long-range RFID readers may utilize automatic matching means that use large non-integrable components to achieve proper tuning. However, this is not a valid option for mobile NFC transceivers. A need exists for methods, systems, and devices related to adaptive calibration circuitry for NFC transceivers. More specifically, a need exists for adaptive matching circuits, and associated methods, for providing optimal performance for varying antenna structures and parts.